package SuperSplit;
use strict;
=head1 NAME
SuperSplit - Provides methods to split/join in two or more dimensions
=head1 SYNOPSIS
use SuperSplit ; #or qw/!:all supersplit/ |which function you want to use
#first example: split on newlines and whitespace and print
#the same data joined on tabs and whitespace. The split works on STDIN
#
print superjoin( supersplit() ); #behaves like while (<>)
{s/\s+/\t/g;print;}
#second: split a table in a text file, and join it to HTML
#
my $array2D = supersplit( \*INPUT ) #filehandle must be open
my $htmltable = superjoin( '</TD><TD>', "</TD></TR>\n <TR><TD>",
$array2D );
$htmltable = "<TABLE>\n <TR><TD>" . $htmltable .
"</TD></TR>\n</TABLE>";
print $htmltable;
#third: perl allows you to have varying number of columns in a row,
# so don't stop with simple tables. To split a piece of text into
# paragraphs, than words, try this:
#
undef $/;
$_ = <>;
tr/.!();:?/ /; #remove punctiation
my $array = supersplit( '\s+', '\n\s*\n', $_ );
# now you can do something nifty as counting the number of words in each
# paragraph
my $i = 0;
for my $rowref (@$array) {
print "Found ".@$rowref." \twords in paragraph \t".++$i."\n";
}
#other uses:
$a = supersplit( 2 ); #behaves like supersplit(), but stops with the
second column
$b = supersplit_open( "<$file", 2 ); #as before, but opens $file for
input
$c = supersplit_open( "<$file"); #as before, but splits as much as it can
$d = supersplit_nolimit( 3); #Hopelessly tries to split on 3.
$e = supersplit_limits( [ ], [2,2] ); #$a, but returns 2x2 array
$f = supersplit_hashref( { separators => [ ], limits => [2,2],
filehandle => \*STDIN }); #as before, but using anonhash to determine
inputs
=head1 DESCRIPTION
Supersplit is just a consequence of the possibility to use
multi-dimensional
arrays in perl. Because that is possible, one also wants a way to
convenienently split data into a nD-array (at least I want to). And vice
versa, of course. Supersplit/join just do that.
Because I intend to use these methods in numerous one-liners and in my
collection of handy filters, an object interface is more often than not
cumbersome. So, this module exports six methods 'super...', but no
variables or globs of any kind. If you think modules shouldn't export
functions, period, use the object interface, SuperSplit::Obj. TIMTOWTDT
If you don't like input magic, you can use the hashref variant. It uses
only little of that ;-).
=over 4
=item supersplit( @separator-list, $filehandleref || $string, $limit);
The first method, supersplit, returns a nD-array. To do that, it needs
data and the strings to split with. Data may be provided as a reference
to
a filehandle, or as a string. If you want use a string for the data, you
MUST provide the strings to split with (>=3 argument mode). If you don't
provide data, supersplit works on STDIN. If you provide a filehandle
(like
\*INPUT), supersplit doesn't need the splitting strings, and
runs in 2D-mode by default. In both cases (STDIN or filehandle only) it
assumes columns are separated by whitespace, and rows are separated by
newlines. Strings are passed directly to split. If you provide more
separators, they will split the higher dimensions. If you only provide
one, it is treated like the column-separator, the row-separator defaults
to
newline.
The separators are processed in reversed order, the last separator is
processed first. This is best explained with a simple whitespace
delimited
table:
1 -1 4.32 new
2 0 3.23 old
3 -1 10.11 old
The default separator list, ('\s+', '\n') first splits on newlines,
resulting in three rows. Each row than is splitted on whitespace,
resulting in four columns every row. The last element of the resulting
array is found by $array->[2][3] (indici start at zero).
You may pass an optional last parameter that contains an integer only.
This is passed to split as the LIMIT parameter. See
L<perlfunc/"split"> for more details, it just limits the number of
times that split splits. The LIMIT paramter is only used in the last
dimension (aka, first delimiter). In case your string can be an
integer only (that means, no other characters present) and you have
more than two dimensions, you should use supersplit_nolimit, or
provide a bogus LIMIT like -1.
A final remark an this function: It first tries to interpret your input
as
a filehandle and than as a string. Maybe you don't want that, if you are
using L<IO::Scalar> for example. In that case, convert your object to a
string before passing it.
Supersplit returns a multi-dimensional array or undef if an error
occurred.
=item supersplit_nolimit
Behaves like supersplit, except that is does not try to interpret the
last
parameter as the LIMIT parameter for split.
=item supersplit_open
Behaves like supersplit (including LIMIT behavior), except that it opens
the input string with open( INPUT, "$string" ). If that fails,
supersplit_open confesses, and it carps if INPUT turns out to be empty.
See L<Carp> for more details.
=item supersplit_limits( $fh || $string, $separator_arrayref,
$limits_arrayref)
Behaves like supersplit, but the separator list must be provided as a
reference to an array, just as the list with LIMITs. If the LIMIT list
has less members than the separator list, the last dimensions will be
called
without LIMIT. Both the separators and limits are popped, that is the
lists
will be processed from right to left, just like the separator list in
previously descrived methods.
This method can be used to parse tables that need a limit on
a higher dimension, I understand the .csv format is an example of that.
=item supersplit_hashref( $hashref)
This is just a wrapper around supersplit_limits. All arguments are passed
as members of the referenced hash. These members are: 'separators',
'limits',
'string', 'filehandle' and 'open'. The members 'separators' and 'limits'
must be
references to arrays. The method passed these references to
supersplit_limits,
see above for a description. On the other arguments, the method tries to
get 'string' first, than the 'filehandle' and if that fails tries to use
the 'open' member.
=item superjoin( $colseparator, $rowseparator, $array2D );
The fourth and last method, superjoin, takes a nD-array and returns it as
a
string. The default behavior assumes 2D-array. In the string, columns
(adjacent cells) are separated by the first argument provided. Rows
(normally lines) are separated by the second argument. Alternatively,
you
may give the 2D-array as the only argument. In that case, superjoin
joins
columns with a tab ("\t"), and rows with a newline ("\n"). If you have
more dimensions in your array, all separators for all dimensions should
be
provided. If you don't, superjoin stops at the second-last dimension.
Just as with supersplit, separators are processed in reversed order: the
last
separator/delimiter is processed first.
Superjoin returns an undef if an error occurred, for example if you give a
ref to an hash. If your first dimension points to hashes or strings,
superjoin will return undef. Mixed arrays will break the code.
=back
=head1 AUTHOR
Jeroen Elassaiss-Schaap, with great help from Ben Tilly, who rewrote most
of
the code for version 0.02.
=head1 LICENSE
Perl/ artisitic license
=head1 STATUS
Alpha
=cut
use Exporter;
use vars qw( %EXPORT_TAGS @ISA $VERSION @limit);
$VERSION = 0.06;
@ISA = qw( Exporter );
%EXPORT_TAGS = (
all => [ qw( supersplit superjoin supersplit_open supersplit_nolimit
supersplit_limits supersplit_hashref)],
standard => [ 'all' ],
minimal => [ qw( supersplit superjoin ) ]
);
Exporter::export_ok_tags('all');
Exporter::export_tags('all');
@limit = ();
use Carp;
sub supersplit{
@_ = _limit( @_);
my $text = _text( pop );
_supersplit( @_, $text);
}
sub supersplit_open{
@_ = _limit( @_);
my $text = _open( pop );
_supersplit( @_, $text);
}
sub supersplit_nolimit{
my $text = _text( pop);
_supersplit( @_, $text);
}
sub supersplit_limits{
my $limit_array = pop;
return undef unless( ref( $limit_array) eq 'ARRAY' );
@limit = @$limit_array;
my $separator_array = pop;
return undef unless( ref( $separator_array) eq 'ARRAY' );
supersplit_nolimit( @$separator_array, @_);
}
sub supersplit_hashref{
my $input = shift;
return undef unless( ref( $input) eq 'HASH' );
my $limit_array = $input->{ limits } or return undef;
my $separator_array = $input->{ separators } or return undef;
my $string;
for (1) {
($string = $input->{ string } and last)
if $input->{ string };
($string = _text( $input->{ filehandle }), last)
if $input->{ filehandle };
($string = _open( $input->{ 'open' } ), last)
if $input->{ 'open' };
}
supersplit_limits( $string, $separator_array, $limit_array);
}
sub _supersplit{
my $text = pop;
$_[0] || ( $_[0] = '\s+' );
$_[1] || ( $_[1] = '\n' );
_split( @_, $text );
}
sub _text{
my $fh = pop;
unless (defined($fh)) {
$fh = \*STDIN;
}
no strict;
do{ local $/ = undef; join '', <$fh>; } || $fh;
}
sub _split{
my $text = pop;
my $limit = $limit[ $#_ ];
my $re = pop;
my @res;
@res = scalar( @limit) ? split( $re, $text, $limit) :
split( $re, $text );
if (@_) {
@res = map { _split( @_, $_) } @res;
}
\@res;
}
sub _limit{
local $_ = $_[$#_];
@limit = (pop) if m/^-?\d+$/s;
if (scalar( @limit))
{
for ( @_[0..($#_ - 1)] )
{
push( @limit, undef);
}
}
@_;
}
sub _open{
my $str = pop;
open INPUT, "$str" || confess "Could not open $str";
my $text = join '', <INPUT>;
close INPUT;
$text || carp "Opening $str did not result in any data";
}
sub superjoin{
my $array_ref = pop;
push ( @_, "\t") if @_ < 1;
push ( @_, "\n") if @_ < 2;
return undef unless( ref( $array_ref ) eq 'ARRAY' );
return undef unless( ref( $array_ref->[0] ) =~ /ARRAY/ );
my @newarray = map{ [ @$_ ] } @$array_ref;
_join( @_, \@newarray);
}
sub _join{
my $array_ref = pop;
my $str = pop;
if (@_) {
@$array_ref = map {_join( @_, $_)} @$array_ref;
}
join $str, @$array_ref;
}
1;